In Reflections and Replies: Essays on the Philosophy of Tyler Burge edited by Martin Hahn and Bjorn Ramberg, MIT Press, 2003 Mental Paint Ned Block New York University The greatest chasm in the philosophy of mind--maybe even all of philosophy-- divides two perspectives on consciousness. The two perspectives differ on whether there is anything in the phenomenal character of conscious experience that goes beyond the intentional, the cognitive and the functional. A convenient terminological handle on the dispute is whether there are “qualia”, or qualitative properties of conscious experience. Those who think that the phenomenal character of conscious experience goes beyond the intentional, the cognitive and the functional believe in qualia.1 The debates about qualia have recently focused on the notion of representation, with issues about functionalism always in the background. All can agree that there are representational contents of thoughts, for example the representational content that virtue is its own reward. And friends of qualia can agree that experiences at least sometimes have representational content too, e.g. that something red and round occludes something blue and square. The recent focus of disagreement is on whether the phenomenal character of experience is exhausted by such representational contents. I say no. Don’t get me wrong. I think that sensations--almost always--perhaps even always--have representational content in addition to their phenomenal character. What’s more, I think that it is often the phenomenal character itself that has the representational content. What I deny is that representational content is all there is to phenomenal character. I insist that phenomenal character outruns representational content. I call this view “phenomenism”. Phenomenists believe that phenomenal character outruns not only representational content but also the functional and the cognitive, hence they believe in qualia. This paper is a defense of phenomenism against representationism, hence issues of reduction of the phenomenal to the functional or the cognitive won't play much of a role. First I will briefly discuss an internalist form of representationism, then I will go on to the main topic of the paper, externalist forms of the view. Internalism One form of representationism holds that the phenomenal character of experience is its “narrow intentional content”, intentional content that is “in the head” in Putnam’s phrase. That is, heads that are the same in ways that don’t involve relations to the environment share all narrow intentional contents. A full dress discussion of this view would discuss various ideas of what narrow intentional content is supposed to be. But 1 I actually prefer a definition of qualia as features of experience that cannot be philosophically reduced to the non-phenomenal, in particular the cognitive, the representational or the functional. (I think that they could be empirically reduced.) But this view will play no role in this paper. Philosophical reduction differs from scientific reduction in the former’s “armchair” nature. The extreme case of philosophical reduction is conceptual reduction. Page 2 of 34 —Mental Paint 01/27/04 this isn’t a full dress discussion. I will simply say that all versions of this view that I can think of that have even the slightest plausibility (and that aren’t committed to qualia) are functionalist. They are functionalist in that they involve the idea that narrow intentional content supervenes on internal functional organization as well as physico-chemical configuration. That is, there can be no differences in narrow intentional contents without corresponding differences at the level of causal interactions of mental states within the head. The view comes in different flavors: functional organization can be understood in terms of the interactions of common-sense mental states or in terms of the causal network of computational states. In both cases, there is a level of “grain” below which brain differences make no differences. One functional organization is multiply realizable physico-chemically in ways that make no difference in narrow intentional content. In other words, there is a level of organization above the level of physiology (“mental” or “computational”) that determines narrow intentional content. (Tye, 1994 takes this view and I understand Rey, 1992a, 1992b and White, 1995 as endorsing it.) Of course phenomenists can (and should) be internalists about phenomenal character too. But phenomenists can allow that phenomenal character depends on the details of the physiology or physico-chemical realization of the computational structure of the brain. Of course, there are also dualist forms forms of phenomenism, but both the physicalist and dualist forms of phenomenism agree that there is no need to suppose that qualia supervene on functional organization. There is a very simple thought experiment that raises a serious (maybe fatal) difficulty for any such (functionalist) internalist form of representationism. Suppose that we raise a child (call her Erisa) in a room in which all colored surfaces change color every few minutes. Further, Erisa is allowed no information about grass being green or the sky being blue, etc. The result is that Erisa ends up with no standing beliefs that distinguish one color from another. Suppose further that she is not taught color words, nor does she make them up for herself. (There are many languages which have only two words for colors, for example the language of the Dani famously studied by Rosch (1972)). Now we may suppose that the result is that there is little in the way of abiding functional differences among her color experiences Most importantly, Erisa has no associations or behavioral inclinations or dispositions towards red that are any different from her associations or inclinations or dispositions towards blue. Of course, she responds to color similarities and differences—e.g., she groups blue things together as having the same color, and she groups red things together as having the same color. But her ability to group under the same color relation does not distinguish her reaction to red from her reaction to blue. The experience as of red is vividly different from the experience as of blue. But what difference in function in this case could plausibly constitute that difference? The challenge to the internalist representationist, then, is to say what the difference is in internal intentional content between the experience of red and the experience of blue? The only resources available to the internalist representationist are functional. There is a difference in phenomenal character, so the internalist Page 3 of 34 —Mental Paint 01/27/04 representationist is committed to finding a difference in function. But the example is designed to remove all abiding differences in function. The functionalist can appeal to temporary differences. Erisa will say “The wall is now the same color that adorned the table a second ago,” and “For one second, the floor matched the sofa.” But these beliefs are fleeting, so how can they constitute the abiding differences between the phenomenal character of her experience of red and green? The differences between these phenomenal characters stay the same (for us) from moment to moment, day to day, and there is no reason to suppose that the same cannot be true for Erisa. The point of the thought experiment is to make it plausible that color experiences can remain just as vivid and the differences between them just as permanent as they are for us even if the functional differences between them attenuate to nothing that could plausibly constitute those differences. Of course, there is one abiding difference in functional role between the experience of red and the experience of green—the properties of the stimuli. Since we are talking about internalist representationism, the stimuli will have to be, e.g. light hitting the retina rather than colored surfaces. But these differences in the stimuli are what cause the differences in the phenomenal character of experience, not what constitutes those phenomenal differences. I don’t expect diehard functionalists to recant in response to this point, but I really don’t see how anyone with an open mind could take the being caused by certain stimuli as constituting phenomenal characters of color experiences. Of course, there may be innate behavioral differences between the experience of red and the experience of blue. Perhaps we are genetically programmed so that red makes us nervous and blue makes us calm. In my view it is a bit silly to suppose that the phenomenal character of the experience as of blue is constituted by such factors as causing calmness. But since so many philosophers feel otherwise, I will also note that despite claims of this sort (Dennett, 1991), such assertions are empirical speculations. (See Dennett’s only cited source, Humphrey, 1992, which emphasizes the poor quality of the empirical evidence.). And of course anyone who holds that representationism is a conceptual truth will be frustrated by the fact that we don't know without empirical investigation whether it is a truth at all. Perhaps the internalist will say that there would be no differences among Erisa’s experiences. Red would of necessity look just the same to her as yellow. But this is surely an extraordinary thing for the internalist to insist on. It could be right of course, but again it is surely an unsupported empirical speculation. I claim that an Erisa of the sort I described is conceptually possible. The replies I have just considered do not dispute this, but instead appeal to unsupported empirical claims. But physicalism is an empirical thesis, so why should the representationist be embarrassed about making an empirical claim? Answer: physicalism is a very general empirical thesis having to do with the long history of successes of what can be regarded Page 4 of 34 —Mental Paint 01/27/04 as the physicalist research program.